A typical rack assembly, for instance used as a display rack, comprises upright posts to which are secured platforms or shelves that are used to support merchandise, art objects, or the like to be viewed. For best effect the items held by the rack should be illuminated, so some sort of accent lighting is provided European patent document 126,023 and Swiss patent 664,997 describe an arrangement wherein conductors are built in to at least one of the rails so that these conductors can be tapped to power lamps at any location along the rail.
At best such arrangements are difficult to set up and difficult to adapt to different requirements. Once provided with lamps, even where the supply lines can be hidden, it is usually impossible to change the lighting at one level without having to redo the entire assembly. Another disadvantage is that any unlighted level is normally left unhighlighted or so dark that it is not noticed at all.